- Add TRANSCRIPT_DAG_STATUS handler to UserEventsProvider with
DagStatusContext and useDagStatusMap hook for live DAG task updates
- Clean up dagStatusMap entries when TRANSCRIPT_STATUS transitions
away from "processing"
- Create DagProgressDots component rendering color-coded dots per
DAG task (green=completed, blue pulsing=running, hollow=queued,
red=failed, gray=cancelled) with humanized tooltip names
- Wire dagStatusMap through browse page -> TranscriptCards ->
TranscriptStatusIcon, falling back to REST dag_status field